A recurring difficulty with hand-held power tools is a lack of an easily mounted vibrational isolator between the tool motor housing and the tool handle. Vibrations being transmitted to a tool handle can cause discomfort to certain user's. Another hurdle in the related art is pneumatically sealing the power tool handle to the motor housing where the handle delivers compressed air and exhausts expanded air to and from the motor housing. Yet another difficulty arises in arriving at tool handles that provide a convenient and comfortable hand/wrist position for a user.
Manufacturers and developers have created a number of vibration isolators to prevent vibration transmission to a user. For example, U.S. Pat. No. 2,058,583 to Forss, illustrates a vibration isolator 16 for isolating the handle 9 from the motor housing 1. U.S. Pat. No. 3,968,843 to Shotwell also provides a vibration isolator 30, 32, 34. Further, WO 94/16864 to Gwinn discloses a vibration isolator 10 enclosed within a power tool housing. The vibration isolators discussed above require elaborate handle to housing fastener setups that prevent the provision of adjustable handles and are limited to isolators being in alignment with the housing.
With regard to sealing the handle to the housing, separate sealing structures are oftentimes required altogether. For instance, in U.S. Pat. No. 3,968,843 to Shotwell, a liner 40 separate from the isolator 30 is used to provide a sealed passage. The additional structure adds weight and complexity to the power tool. The related art also fails to sufficiently address the sealing of a handle where the handle both delivers and exhausts air to and from the motor housing.
With regard to adjustable handles, the related art has utilized straight, side, angled or spade handles in order to achieve a correct hand/wrist position. The difficulty with this concept is that the operator has to do a variety of different jobs with the same tool. Thus, a straight handled tool may be ideal for one application but not ideal on another application where a turned or angled handle is better suited.
In an attempt to overcome this limitation, power tool developers and manufacturers have introduced adjustable type handles for their power tools and varied vibration isolators. For example, U.S. Pat. No. 4,522,270 issued to Kishi discloses a hand-held power tool which provides a handle that pivots angularly with respect to the tool housing. Similarly, U.S. Pat. No. 3,571,874 issued to Von Arx discloses a descaling device which also has a handle that pivots angularly with respect to the tool housing. These inventions allow the tool handle to be angularly pivoted toward or away from the tool attachment/impact point. This gives the operator an increased ability to find a more comfortable or efficient handle position which he or she lacked in the past.
While the aforementioned patents provide a certain amount of improvement with regard to handle comfort, there are still difficulties which these devices do not address. For instance, given that most tools have a trigger on the handle, these devices do not have the ability to change the direction of the trigger with respect to the tool housing. In other words, the trigger always faces in the same direction--towards the tool attachment/impact point. Under certain circumstances, in order to achieve the ideal hand/wrist position, an operator may want to have the trigger facing a direction other than that of the direction of the tool. Further, the rotatable handle tools heretofore used do not provide sufficient vibration isolation between the motor housing and handle and, further, do not address the sealing of the handle to the motor housing where such sealing is necessary.
Accordingly, until now, there has been a long-felt need for a power tool having a structure that vibrationally isolates and seals a handle to a motor housing in a single, easily mounted structure where the handle delivers/exhausts air to the housing. Further, there has been a long-felt need for a structure that addresses the above noted problems and also allows for adjustment of the handle relative to the motor housing. The present invention seeks to provide this functionality.